High-accuracy mixing of substances is important in a wide variety of technical fields, including microelectronics (in the formation of semiconductors, flat panel displays, disk drives, solar cells, and the like), life sciences (pharmaceutical, biotechnology and personal care, among others), chemical engineering and petrochemical engineering. For example, manufacturing innovations, such as single wafer processing in semiconductor manufacturing and continuous reaction processes in pharmaceutical manufacturing, often require chemical substances to be mixed in precise proportions.